Tropical Storm Arthur a potential long range threat to the region Update One
WTNT41 KNHC 030255
TCDAT1
TROPICAL STORM ARTHUR DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012014
1100 PM EDT WED JUL 02 2014
Reports from Air Force Reserve and NOAA Hurricane Hunter aircraft,
along with satellite data, indicate that Arthur is very near
hurricane strength. On one side, the central pressure has fallen to
988 mb, there were a few estimates of hurricane force winds from
the SFMR instrument on the Air Force plane, and there are several
satellite intensity estimates of 65-75 kt. On the other side, the
flight-level winds from the two aircraft did not support hurricane
strength, and the SFMR winds from the NOAA plane were also below
hurricane strength. Given the conflicting data, the initial
intensity is held at 60 kt. Another aircraft is scheduled to
investigate Arthur around 06Z.
The initial motion is now 360/7. Arthur is moving through a
weakness in the subtropical ridge towards the westerlies over the
eastern United States. During the next 24-36 hours, the cyclone
should recurve northeastward ahead of a deep-layer baroclinic
trough moving eastward through the Great Lakes and New England.
While the guidance is in good agreement with this scenario, the
center of the guidance envelope has again shifted a little westward
toward the North Carolina coast. The GFS has made a rather
significant shift since the previous run, and it now brings the
center of Arthur across eastern North Carolina. The new forecast
track is shifted a little closer to the coast, but it will stay in
the center of the guidance envelope to the east of the GFS.
Coastal radar data shows that Arthur is having trouble maintaining a
closed eyewall, which is likely due to continued entrainment of dry
air. However, the storm should remain in an area of light vertical
wind shear and over warm sea surface temperatures for the next 36
hours or so. Thus, the new intensity forecast calls for additional
strengthening during that time similar to the previous forecast.
After 48 hours, Arthur should merge with the baroclinic trough over
the Canadian Maritimes and become extratropical. The intensities
and wind radii during the extratropical phase have been modified
based on input from the Ocean Prediction Center.
The new experimental potential storm surge flooding map is
available at:
www.nhc.noaa.gov/graphics_at1.shtml?inundation
FORECAST POSITIONS AND MAX WINDS
INIT 03/0300Z 30.6N 79.1W 60 KT 70 MPH
12H 03/1200Z 31.7N 78.9W 65 KT 75 MPH
24H 04/0000Z 33.5N 77.4W 70 KT 80 MPH
36H 04/1200Z 36.0N 74.5W 75 KT 85 MPH
48H 05/0000Z 39.0N 70.7W 75 KT 85 MPH
72H 06/0000Z 45.5N 63.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
96H 07/0000Z 51.0N 55.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
120H 08/0000Z 55.5N 50.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
$$
Forecaster Beven
000
FXUS61 KCAR 030052
AFDCAR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CARIBOU ME
852 PM EDT WED JUL 2 2014
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL REMAIN ACROSS THE REGION THROUGH
THURSDAY. A SLOW MOVING COLD FRONT WILL BEGIN TO APPROACH LATE
TONIGHT...THEN VERY SLOWLY CROSS THE REGION FRIDAY NIGHT. ARTHUR
WILL MOVE IN THE DIRECTION OF EASTERN NOVA SCOTIA FROM THE OPEN
ATLANTIC BY SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
850 PM: UPDATE TO REMOVE SVR TSTM WATCH 388. ISOLATED
THUNDERSTORMS AND SHOWERS WILL CONTINUE TONIGHT. MINOR
ADJUSTMENTS TO THE HRLY TEMPS...POPS AND ASSOCIATED WEATHER GRIDS.
ORGNL DISC: LATEST RADAR SHOWS INITIAL STRONG TSTMS MOVING INTO
THE W CNTRL PTNS OF THE FA FROM WRN ME. LATEST BUFKIT
SOUNDINGS/LAPS DATA SUGGESTS MIXED MODE CNVCTV CELL TYPES INTO THE
ERLY EVE...WITH HIGH WIND THE PRIMARY THREAT AND LARGE HAIL
SECONDARY (HIGH FZL WORKING AGAINST LARGE HAIL IN THE ABSENCE OF
MESO-CYCLONE ROTATION).
WILL KEEP ENHANCED TSTM WORDING THRU THE ENTIRE EVE. OTHERWISE...
ACTIVITY WILL WIND DOWN LATE TNGT.
ANOTHER ROUND OF CNVCTN FEATURING MORE IN THE WAY OF HVY RNFL CAN
BE XPCTD THU AFTN...WITH ISOLD SVR WIND AND HAIL STILL POSSIBLE.
OVRNGT LOWS WILL BE WARM AGAIN...BUT LIKELY NOT AS WARM AS LAST
NGT OVR MUCH OF THE AREA DUE TO THE POTENTIAL OF CONVECTIVELY
COOLED AIR. HI TEMPS THU SHOULD ALSO BE SEVERAL DEG COOLER ACROSS
THE FA THAN TDY DUE TO GREATER CLD CVR AND SLIGHTLY COOLER 925-850MB
TEMPS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT...CONVECTION WILL CONTINUE INTO THE EVENING FOR
NORTHERN MAINE ALONG THE STALLED FRONTAL BOUNDARY. WITH PWATS
NEARING 2 INCHES...DEW POINTS NEAR 70F...A DEEP WARM CLOUD LAYER
AND THE POSSIBILITY OF CELLS TRAINING ALONG THE STALLED
FRONT...FLASH FLOODING REMAINS A CONCERN. EVEN THOUGH AFTERNOON
CONVECTION WILL DIMINISH IN THE EVENING...HEAVY SHOWERS COULD
RENEW AFTER MIDNIGHT AS A LOW PRESSURE MOVES NORTHEAST ALONG THE
STAGNANT FRONT. THIS LOW WILL BE STRENGTHENED BY AN APPROACHING
UPPER TROUGH FROM THE GREAT LAKES REGION. THE BIGGEST AREA OF
CONCERN FOR HEAVY RAINFALL WILL IN THE CROWN OF MAINE. SMALL
STREAMS AND NORMALLY SUSCEPTIBLE TOWNS SUCH AS VAN BUREN COULD BE
IMPACTED RATHER THAN MAIN STEM RIVERS. LOWS ON THURSDAY NIGHT WILL
BE IN THE LOW TO MID 60S FOR MOST LOCATIONS.
ON FRIDAY...THE FRONT REMAINS STALLED OVER THE FORECAST AREA.
CLOUDS AND SHOWERS WILL LINGER OVER THE AREA BUT WHETHER THERE CAN
BE ENOUGH HEATING TO GENERATE STRONG CONVECTION REMAINS IN DOUBT.
THE UPPER LEVEL TROUGH STAYS WEST AND WILL PROVIDE LIFT. THE
BIGGEST RISK FOR THUNDERSTORMS SHIFTS SOUTHWARD TO SOUTH OF HOULTON TO
INCLUDE BANGOR AFTER MORNING CLOUDS BURN OFF. ADDED A CHANCE OF
THUNDERSTORMS FOR MUCH OF SOUTHERN AROOSTOOK AND INTERIOR DOWN
EAST IN THE AFTERNOON...BUT THERE ARE NOT ANY CLEAR INDICATIONS OF
SEVERE POTENTIAL AT THIS TIME. TEMPERATURES WILL BE COOLER WITH
READINGS IN THE MID 70S...EXCEPT A FEW 80F READINGS POSSIBLE FOR
INTERIOR DOWN EAST.
TS ARTHUR RIDES NORTH ALONG THE FRONT FRIDAY NIGHT AND SEEMS
POISED TO BRING SOME HEAVY RAINFALL TO DOWN EAST...ESPECIALLY
ALONG THE COAST ON FRIDAY NIGHT. LOWS WILL BE IN THE UPPER 50S TO
LOW 60S.
MOST GUIDANCE IS INDICATING THAT THE FRONT MOVES CLEANLY THROUGH
THE FORECAST AREA BY SATURDAY MORNING WITH THE POSSIBLE EXCEPTION OF
COASTAL WASHINGTON AND HANCOCK COUNTIES...DEPENDING ON THE TRACK
OF TS ARTHUR. HIGHS WILL BE MUCH COOLER IN THE UPPER 60S TO LOW 70S
WITH LOWER HUMIDITY AND SUNSHINE LIKELY EXCEPT PERHAPS WASHINGTON
COUNTY.
FXCN31 CWHX 030000
TROPICAL CYCLONE TECHNICAL INFORMATION STATEMENT ISSUED BY THE
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 8.44 PM ADT
WEDNESDAY 02 JULY 2014.
THE NEXT STATEMENT WILL BE ISSUED BY 3.00 AM ADT
1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION
AT 9.00 PM ADT, TROPICAL STORM ARTHUR WAS LOCATED NEAR LATITUDE 30.1
N AND LONGITUDE 79.0 W, ABOUT 153 NAUTICAL MILES OR 284 KM NORTHEAST
OF ORLANDO. MAXIMUM SUSTAINED WINDS ARE ESTIMATED AT 60 KNOTS (111
KM/H) AND CENTRAL PRESSURE AT 992 MB. ARTHUR IS MOVING NORTH AT 6
KNOTS (11 KM/H).
2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH
DATE TIME LAT LON MSLP MAX WIND
ADT MB KTS KMH
JUL 02 9.00 PM 30.1N 79.0W 992 60 111
JUL 03 9.00 AM 32.0N 78.3W 990 65 120
JUL 03 9.00 PM 33.9N 76.6W 989 70 130
JUL 04 9.00 AM 36.2N 73.7W 986 75 139
JUL 04 9.00 PM 39.0N 70.0W 986 75 139
JUL 05 9.00 AM 41.9N 66.4W 988 70 130
JUL 05 9.00 PM 44.5N 63.5W 989 65 120 POST-TROPICAL
JUL 06 9.00 AM 46.9N 60.6W 991 55 102 POST-TROPICAL
JUL 06 9.00 PM 49.6N 57.2W 991 50 93 POST-TROPICAL
JUL 07 9.00 AM 52.3N 52.8W 991 45 83 POST-TROPICAL
3. TECHNICAL DISCUSSION
A. ANALYSIS
ARTHUR IS NEAR HURRICANE INTENSITY NOW AS IT MOVES SLOWLY NORTHWARD
NOT FAR EAST OF FLORIDA. WATER TEMPERATURES ARE PLENTY WARM FOR
FURTHER INTENSIFICATION. LAND-BASED RADAR OVER FLORIDA ALSO SHOWS THE
STORM CORE BECOMING MORE ORGANIZED WITH A CLOSED EYEWALL.
B. PROGNOSTIC
WITH A TROUGH OF LOW PRESSURE EXPECTED TO EVENTUALLY MERGE WITH
ARTHUR THIS WEEKEND, WE EXPECT THE STORM TO BE IN A "HYBRID STATE"
WHEN IT MOVES THROUGH OR TRACKS OFFSHORE. WE WILL HAVE MORE
METEOROLOGICAL ANALYSES WITH OUR NEXT FORECAST PACKAGE AT 9 PM ADT.
C. PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
03/00Z 70 70 60 50 30 30 0 30 0 0 0 0
03/12Z 80 80 60 60 50 50 0 30 30 30 0 0
04/00Z 95 95 60 70 55 60 25 35 30 35 10 15
04/12Z 105 115 65 75 60 65 35 35 30 45 10 10
05/00Z 115 135 80 90 65 80 45 45 30 50 10 15
05/12Z 130 155 95 105 75 90 50 50 30 50 10 20
06/00Z 165 180 100 115 95 90 50 55 0 0 0 0
06/12Z 200 210 100 120 115 90 45 60 0 0 0 0
07/00Z 210 225 100 120 120 90 45 60 0 0 0 0
07/12Z 210 225 100 120 0 0 0 0 0 0 0 0
END/HATT/FOGARTY
posted by Advackia at 8:55 PM
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